Scour Critical Bridges
23,522 bridges across the US at risk from water erosion around foundations.
Scour Critical Bridges
Scour is the erosion of soil and rock around a bridge's foundation caused by moving water. When foundations are exposed or undermined, a bridge can collapse even if its deck and superstructure are in good condition. Scour is the leading cause of bridge failures in the US. These 23,522 bridges have been identified as vulnerable to scour damage.
| Bridge | State | Scour Status | Condition | Year Built | ADT |
|---|---|---|---|---|---|
| MILL RIVER | Connecticut | Scour Critical — Countermeasures Installed | Poor | 1935 | 6,505 |
| NORTH CHICKAMAUGA CREEK | Tennessee | Scour Critical — Countermeasures Installed | Good | 1983 | 6,505 |
| GUM CREEK | Georgia | Scour Critical — Countermeasures Installed | Good | 1990 | 6,502 |
| S FORK SNOQUALMIE RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1941 | 6,500 |
| ONION RIVER | Wisconsin | Scour Critical — Countermeasures Installed | Good | 1961 | 6,500 |
| GUNNISON RIVER | Colorado | Scour Critical — Countermeasures Installed | Fair | 1966 | 6,500 |
| CERRO GORDO CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1960 | 6,500 |
| PROVIDENCE RIVER | Rhode Island | Scour Critical — Countermeasures Installed | Poor | 1996 | 6,500 |
| SMITH RIV SOUTH BANK RD | California | Scour Critical — Countermeasures Installed | Fair | 1940 | 6,500 |
| CRUZ CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1942 | 6,500 |
| CA%AS RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1947 | 6,500 |
| SECRET RAVINE | California | Scour Critical — Countermeasures Installed | Fair | 1929 | 6,490 |
| SANDY RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1930 | 6,481 |
| COLE CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1965 | 6,480 |
| MILL BROOK | New Hampshire | Scour Critical — Countermeasures Installed | Fair | 1928 | 6,478 |
| SKULLS CREEK | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1954 | 6,478 |
| TANG RIVER RELIEF | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1955 | 6,478 |
| TANGIPAHOA RIVER RELIEF | Louisiana | Scour Critical — Countermeasures Installed | Good | 1986 | 6,478 |
| SHELL HARBOR CANAL | Florida | Scour Critical — Countermeasures Installed | Fair | 1969 | 6,470 |
| DEER CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1950 | 6,466 |
| MILTON CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1958 | 6,466 |
| OVERFLOW CHANNEL | Oregon | Scour Critical — Countermeasures Installed | Fair | 1970 | 6,459 |
| WISSAHICKON CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1841 | 6,457 |
| Tacony Creek | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1914 | 6,455 |
| SKEEBO BRANCH | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1958 | 6,450 |
| TUALATIN RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1971 | 6,446 |
| ROCKAWAY RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1910 | 6,446 |
| HAW CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1930 | 6,443 |
| STREAM | Washington | Scour Critical — Countermeasures Installed | Fair | 1937 | 6,441 |
| OUTLET BROOK | New York | Scour Critical — Countermeasures Installed | Poor | 1984 | 6,437 |
| DRAIN | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1939 | 6,435 |
| DRAIN | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1939 | 6,435 |
| TANGIPAHOA RIVER | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1939 | 6,435 |
| OVER DUTCHMAN RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1947 | 6,433 |
| OVER DUTCHMANS RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1948 | 6,433 |
| HONEY CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1974 | 6,433 |
| TIJERAS CANYON | New Mexico | Scour Critical — Countermeasures Installed | Fair | 1968 | 6,431 |
| LONG TOM RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1963 | 6,426 |
| MILL CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1990 | 6,424 |
| 47 MILE CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1931 | 6,417 |
| WILSON CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1931 | 6,417 |
| WYLIE RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1905 | 6,411 |
| S FK SKYKOMISH RIVER | Washington | Scour Critical — Countermeasures Installed | Poor | 1933 | 6,408 |
| SOUHEGAN RIVER | New Hampshire | Scour Critical — Countermeasures Installed | Fair | 1917 | 6,406 |
| CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1950 | 6,400 |
| LOCUST CREEK | Arkansas | Scour Critical — Countermeasures Installed | Fair | 1947 | 6,400 |
| HONDA CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1891 | 6,400 |
| HONDA CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1891 | 6,400 |
| SAGER CREEK | Arkansas | Scour Critical — Countermeasures Installed | Fair | 1985 | 6,400 |
| WHITAKER CREEK | Florida | Scour Critical — Countermeasures Installed | Good | 1959 | 6,400 |
Scour Critical Bridges by State
States ranked by number of scour critical bridges.
| State | Scour Critical | Unaddressed | Countermeasures | Ineffective |
|---|---|---|---|---|
| Texas | 3,912 | 75 | 516 | 3,321 |
| Pennsylvania | 2,233 | 45 | 2,187 | 1 |
| Louisiana | 1,302 | 13 | 1,288 | 1 |
| South Carolina | 1,263 | 0 | 1,217 | 46 |
| Oregon | 1,231 | 4 | 1,221 | 6 |
| Michigan | 1,081 | 14 | 1,062 | 5 |
| Nebraska | 962 | 224 | 732 | 6 |
| New York | 864 | 9 | 780 | 75 |
| Indiana | 756 | 7 | 749 | 0 |
| Wisconsin | 751 | 0 | 748 | 3 |
| Kansas | 638 | 9 | 626 | 3 |
| California | 623 | 27 | 562 | 34 |
| Tennessee | 581 | 12 | 569 | 0 |
| Washington | 516 | 14 | 487 | 15 |
| Puerto Rico | 496 | 9 | 487 | 0 |
| Alabama | 450 | 1 | 423 | 26 |
| Iowa | 392 | 3 | 385 | 4 |
| New Jersey | 362 | 2 | 360 | 0 |
| Florida | 357 | 4 | 339 | 14 |
| Oklahoma | 317 | 33 | 283 | 1 |
| Missouri | 312 | 4 | 307 | 1 |
| Mississippi | 301 | 6 | 286 | 9 |
| Connecticut | 279 | 0 | 276 | 3 |
| Minnesota | 257 | 38 | 202 | 17 |
| Vermont | 242 | 0 | 240 | 2 |
| Colorado | 241 | 3 | 238 | 0 |
| Idaho | 215 | 18 | 186 | 11 |
| South Dakota | 207 | 3 | 203 | 1 |
| Arkansas | 187 | 3 | 129 | 55 |
| Massachusetts | 166 | 15 | 106 | 45 |
| Montana | 166 | 13 | 140 | 13 |
| Arizona | 164 | 2 | 160 | 2 |
| West Virginia | 160 | 2 | 98 | 60 |
| Alaska | 159 | 1 | 146 | 12 |
| Maine | 140 | 13 | 126 | 1 |
| North Carolina | 130 | 9 | 105 | 16 |
| New Mexico | 127 | 4 | 114 | 9 |
| North Dakota | 102 | 14 | 87 | 1 |
| Utah | 100 | 6 | 82 | 12 |
| Georgia | 99 | 1 | 81 | 17 |
| Illinois | 99 | 3 | 85 | 11 |
| Nevada | 94 | 0 | 85 | 9 |
| Rhode Island | 94 | 0 | 93 | 1 |
| New Hampshire | 86 | 2 | 78 | 6 |
| Hawaii | 83 | 0 | 82 | 1 |
| Kentucky | 56 | 16 | 39 | 1 |
| Maryland | 54 | 1 | 51 | 2 |
| Wyoming | 51 | 1 | 48 | 2 |
| Delaware | 39 | 0 | 39 | 0 |
| Ohio | 12 | 2 | 4 | 6 |
| Virginia | 8 | 0 | 8 | 0 |
| District of Columbia | 5 | 0 | 4 | 1 |
Scour Critical Rating Codes
| Code 2 — Unaddressed | Bridge is scour critical with no countermeasures installed. The foundation is vulnerable and no protective action has been taken. |
| Code 3 — Countermeasures Installed | Protective measures (riprap, sheet piling, etc.) have been installed to reduce scour risk, but the bridge remains classified as scour critical. |
| Code 6 — Countermeasures Ineffective | Protective measures were installed but have been assessed as ineffective. The bridge requires re-evaluation and additional action. |
About Scour Critical Bridges
Scour critical bridges have been identified through underwater inspection or analysis as having foundations that are unstable or could become unstable during flood conditions. FHWA requires action plans for all scour critical bridges. Famous scour failures include the 1987 Schoharie Creek Bridge collapse in New York.